1. Field of the Invention
The present invention relates hand tools and more particularly, to an improved structure of pliers.
2. Description of the Related Art
A conventional lever-wrench pliers, as shown in FIG. 1, comprises a body 1, a movable jaw 2 pivoted to the body 1, a lever 3 pivoted to the movable jaw 2, a toggle lever 4, which has one end (the fixed end) pivoted to the lever 3 and the other end (the free end) inserted into the inside of the body 1, an adjusting screw 5 threaded into the bottom side of the body 1 and stopped against the free end of the toggle lever 4, a spring 7 connected between the body 1 and the movable jaw 2 to hold the movable jaw 2 in the open position relative to the body 1, and a release lever 6 pivoted to the lever 3 to support the toggle lever 4. Moving the lever 3 relative to the body 1 controls closing/opening of the movable jaw 3 relative to the body 1. Rotating the adjusting screw 5 forwards/backwards relative to the body 1 adjusts the moving distance of the toggle lever 4 and the lever 3 so as to further adjust the opening extent between the movable jaw 2 and the body 1 subject to the workpiece 8 to be locked.
When pressing the release lever 6, the toggle lever 4 is lifted to bias the lever 3 relative to the toggle lever 4, and therefore the movable jaw 2 is turned outwards from the body 1 to release the workpiece 8.
This design of lever-wrench pliers holds the workpiece 8 by clamping the workpiece from two opposite sides. When holding the workpiece 8, the user must apply much force to the body 1 and the lever 3. Further, because the teeth of the jaw tip of the body 1 and the teeth of the movable jaw 2 are respectively formed on a respective flat surface, the lever-wrench pliers may slip from the workpiece 8 during operation.
Therefore, it is desirable to provide a lever-wrench pliers that eliminates the aforesaid drawbacks.